Handheld Device with a User Interface

1. A handheld device comprising: a first body part comprising a first user interface element; a second body part comprising a second user interface element; a link mechanism configured to interconnect the first body part and the second body part movably by a user between a first configuration and a second configuration, wherein the link mechanism comprises at each side of the handheld device only one pivot point at each of the first and second body parts; the first body part and the second body part being stacked in a first order in the first configuration and in a second order opposite to the first order in the second configuration; wherein the first body part and the second body part are each configured to maintain a parallel orientation when the first body part and the second body part are moved between the first and second configurations; wherein the first body part and the second body part have been configured to maintain their parallel orientation throughout changing from the first configuration to the second configuration.

2. A handheld device according to claim 1 , wherein the first and second body parts each have thickness substantially smaller than width and length.

3. A handheld device according to claim 1 , wherein the first and second body parts each have differing widths and lengths.

4. A handheld device according to claim 1 , wherein the link mechanism has been configured to provide a third configuration between the first and second configuration such that the first body part and the second body parts are positioned sequentially.

5. A handheld device according to claim 4 , wherein the first and second body parts have been located in a common plane in the third configuration.

6. A handheld device according to claim 1 , wherein the link mechanism comprises two arms spaced apart of each other.

7. A handheld device according to claim 6 , wherein at least one of the arms comprises orientation control equipment configured to control the parallel orientation of the first and second body parts during change between the first and second configuration.

8. A handheld device according to claim 1 , wherein the device further comprises orientation control equipment at two opposite sides of the device.

9. A handheld device according to claim 8 , wherein the device further comprises a force transmission system configured to link the orientation control equipment at the two opposite sides so as to reduce twist between the two body parts.

10. A handheld device according to claim 1 , wherein the link mechanism further comprises a shaft; and gears connecting the shaft to the first and second body parts at the respective pivot points.

11. A handheld device according to claim 1 , wherein the device further comprises a processor and a memory configured to store instructions for the processor.

12. A handheld device according to claim 11 , wherein the processor has been configured to provide different services according to instructions stored in the memory.

13. A handheld device according to claim 12 , wherein the processor has been configured to process different services selectively depending on the configuration of the body parts.

14. A handheld device according to claim 13 , wherein the first and second body parts comprise a first display and a second display, respectively.

15. A handheld device according to claim 14 , wherein the first and second displays are assigned at a given time to respective first and second services and the processor is configured to select as currently operated service the service corresponding to the display that is stacked on top of the remaining display.

16. A handheld device according to claim 1 , wherein the first and second body parts each comprise a first display and a second display, respectively.

17. A handheld device according to claim 16 , wherein the device further comprises a processor and a memory configured to store instructions for the processor and the displays have been functionally connected to the processor.

18. A handheld device comprising: a first body part comprising a first user interface element; a second body part comprising a second user interface element; means for interconnecting the first body part and the second body part movably by a user between a first configuration and a second configuration, wherein the means for interconnecting the first body part and the second body part comprises at each side of the handheld device only one pivot point at each of the first and second body parts; the first body part and the second body part being stacked in a first order in the first configuration and in a second order opposite to the first order in the second configuration; wherein the first body part and the second body part are each configured to maintain a parallel orientation when the first body part and the second body part are moved between the first and second configurations; wherein the first body part and the second body part have been configured to maintain their parallel orientation throughout changing from the first configuration to the second configuration.

19. A computer program embodied in a non-transitory physical memory medium for controlling a handheld device that comprises a first body part and a second body part with respective displays and connected such that the first and second body parts are stackable in reversible order, the program comprising: computer executable program code configured to cause the handheld device to present first content on the first body part and no content on the second body part when the device is in a first configuration; computer executable program code configured to cause the handheld device to present no content on the first body part and second content on the second body part when the device is in a second configuration; and computer executable program code configured to cause the handheld device to present third content on the first body part and fourth content on the second body part when the device is in the first configuration; wherein the computer executable program code is also configured to cause the handheld device to present content corresponding to maintaining a parallel orientation of the first body part and the second body part when the first body part and the second body part are moved between the first and second configurations; wherein the computer executable program code′ is also configured to cause the first body part and the second body part to be configured to maintain their parallel orientation throughout changing from the first configuration to the second configuration; and wherein the first body part and the second body part are connected by a link mechanism comprising at each side of the handheld device only one pivot point at each of the first body part and the second body part.

20. A computer program according to claim 19 , wherein the third content corresponds to the first content and the fourth content corresponds to the second content.

21. A computer program according to claim 19 , wherein: the first and second contents are independent of each other; and the third content and the fourth content collectively represent common content.